Just converts the files 1-by-1, you cannot select several files for conversion which would then be converted one after the other.

That is possible with Wondershare UniConverter which is number one in toptenreviews for converters but has an abysmal converting quality: if the original flv file isn't that good, the converted mp4 target file is unviewable.

Here with Dimo FLV Converter the default target mp4 files (other formats are available, I didn't tried them) isn't better than the original file quality of course, but it is not worse either. I cannot say more precisely but I think the original quality is maintained, perhaps not 100 p.c. but then certainly to a high degree, so this program is MUCH better in this respect than the Wondershare thing.